What happens when a utility line is underground? In all cases, you don’t want that line disturbed, be it a drain pipe, sewage line, gas line, or fiber optic cable. If construction or roadwork is going on around your home or area, the utility lines should be labeled in such cases. Also, if you’re a utility crew adding gas, power, or underground telephone lines, you should properly label the area after. Regardless, the area can be labeled with our underground utility tape which, in addition to indicating the type of buried utility line, is colored in green, blue, brown, red, and other colors.